Variable-delivery pump or fluid-pressure motor.



1. ROBSON.

VARIABLE DELIVERY PUMP 0R FLUID PRESSURE MOTOR.

APPLICATION FILED NOV. 8, 1913.

1,147,893. Patented July 27, 1915.

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A] \\i\\ B B ran sreT P T @FMQE" JOHN ROBSON, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNOB. TO VARIABIIE SPEED GEAR LIMITED, OF WESTMINSTER, ENGLAND.

VARIABLE-DELIVERY PUMP 0R FLUID-PRESSURE MOTOR.

Specification ofLetters Patent.

Patented July at, rate.

Application filed November 8, 1913. Serial No. 799,877.

To all whom it may concern:

Be it known that I, J OHN RoBsoN, a subject of the King of Great Britain, residing at Broadway Court, Westminster, in the county of London, England, have invented certain new and useful Improvements in Variable-Delivery Pumps or Fluid-Pressure Motors, of which the following is a specification.

This invention relates to variable delivery pumps or fluid pressure motors of the kind comprising a cylinder barrel having a number of cylinders for-the receptionof pistons provided with piston rods that are pivotally connected to the pistons and to a plate or disk whichis carried by a tilting box the displacement of which (in the case of the pump) with respect to the barrel causes the flow of fluid from the pump to be varied, and in the ease of the motor causes the speed thereof to be varied. The said tilting box of the pump has in some cases been adjusted by means of a screw threaded shaft carried in bearings in. the pump casing and engaging with a nut having trunnions that carry guide bl0cks,these guide blocks being slidably disposed between horns or brackets formed on the tilting box.

It has been found that these horns or brackets are liable to bend. or break especially when the pump is operating under high pressures, and'the chief object of the present invention is to so construct the mechanism for displacing the tilting box that the said horns or brackets can be dispensed with.

According to this invention the tilting box is provided with a projection, preferably of circular cross section, which loosely carries a bearing block rotatably connected to a reciprocatory member, the movement of which by any suitable means effects the displacement of the tilting box.

In order that the said invention may be clearly understood and readily carried into effect the same will be described more fully with reference to the accompanying drawings, in which Figure l is a longitudinal section showing a constructional form of our improvements. Fig. 2 is a transverse section taken approximately on the line 11 of Fig. 1. Fig. 3 is a plan of a portion of Fig. 1, and Fig. 4: is a section showing a slightly modified constructional form.

A is the casing of the pump or motor and B is the tilting box.

B representsthe projection on the tilting box, C the bearing block and C the reciprocatory member.

In the example shown, the bearing block C has convex surfaces which engage with corresponding concave surfaces on the re ciprocatory member C. This member is in the form of a rectangular crosshead suitably guided between ribs A formed on the casing A, and-having a screw threaded rod or spindle C integral therewith or connected thereto. The said ribsare arranged parallel to the axis of the screw threaded rod or spindle C -and serve to prevent angular movement of the said rod or spindle and to take the side thrust which occurs upon the bearing block C during the displacement of the tilting box B. The said screwthreaded rod or spindle engages with a nut C which is carried by the casing A in such manner that it can rotate but cannot move axially. The said nut projects beyond the casing and is adapted to receive a handle by means of which it can be rotated to effect the reciprocatory movement of the rod or spindle. Instead of operating the nut directly by means of a handle, a servo-motor, solenoid or other suitable device may be employed. Suitable thrust washers or bearings C are interposed between a collar 0 on the nut C and a shoulder a of the one ing A, and between the said collar and a removable hearing A in which the nut is mounted. Thelatter bearing is carried by the casing, and is preferably provided with a stuffing box of any suitable construction. In the example shown, the nut C is recessed to receive. a leather lace 0* which lies in con- 0 tact withthe bearing A The bearing block C may, as shown in Fig. l, be made in two halves and the crosshead C may be provided with a screw 0 for the purpose of adjusting the half bearings to compensate for wear. The aforesaid projection B on the tilting box may be situated in any convenient position thereon, and the axis of the screw threaded rod or spindle C may be either normal, parallel, or at any inclination to the longitudinal axis of the pump-a. e. to the axis ofthe driving shaft.

The herein referred to pump and motor generally constitute the pump and motor 1 units of a variable hydraulic transmission ear.

g What I claim and desire to secure by Letters Patent of the United States is 1. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pressure motor, the combination with a tilting member, of a projection on said member, a bearing block loosely carried by and surrounding said projection, a reciprocatory member rotatably connected to said bearing block and means for displacing said reciprocatory member.

2. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pressure ,motor, the combination with a casing of the pump or motor, and a tilting member carried by the casing, of a projection on said member, a bearing block loosely carried by and surrounding said projection, a reciprocatory member rotatably connected to said bearing block, guides in the casing for said reciprocatory member and means for displacing the latter member.

3. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pres sure motor, the combination with a casing of the pump or motor, and a tilting member carried by the casing, of a projection on said member, a bearing block loosely carried by said projection and having convex surfaces, a reciprocatory member rotatably connected to said bearing block, guides in the easing for said reciprocatory member and means for displacing the latter member.

4:. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pressure motor, the combination with a casing of the pump or motor, and a tilting member carried by the casing, of a projection on said member, a bearing block loosely carried by said projection and having convex surfaces, a crosshead engaging with said convex surfaces, guides in the casing for said crosshead and means for displacing the crosshead.

5. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pressure motor, the combination with a casing of the pump or motor, and a tilting member Copies of this patent may be obtained for and the projection.

carried by the casing, of a projection on said member, a bearing block loosely carried by said projection and having convex surfaces, a crossheadengaging with said convex surfaces, guides in the casing for said crosshead, a screw threaded shaft integral with the crosshead, and a rotary nut engaging with the screw threaded shaft.

6. In mechanism ,for varying the delivery of a fluid pump or the speed of a fluid pressure motor, the combination with a casing of the pump or motor, and a tilting member carried by the casing,,of a projection on said member, a bearing block loosely carried by said projection and having convex surfaces, a ,crosshead engaging with said convex surfaces, guides in the. casing for said crosshead, a screw threadedv shaft integral with the crosshead, a rotary nut engaging with said screw threaded shaft, a removable bearing carried by the casing and carrying said nut, a collar on said nut, a projection on the casing and thrust washers interposed between the bearing and the collar and between the collar and the projection.

7. In mechanism for varying the delivery of a fluid pump or the speed of a fluid pressure motor, the combination with a casing of the pump or motor, and a tilting member carried by the casing, of a projection on said member, a bearing block made in two halves loosely carried by said projection and having convex surfaces, a crosshead engaging with said convex surfaces, guides in the casing for said crosshead, a screw threaded shaft integral with the crosshead, a rotary nut engaging with said screw threaded shaft, a removable bearing carried by the casing and carrying said nut, a collar on said nut, a projection on the casing and thrust washers interposed between the bearing and the collar and between the collar In testimony whereof I my signature in presence of two witnesses.

I JNO. ROBSON.

Witnessesz- I '1; SELBY WARDLE, Trros. F. HARGREAvEs.

five cents each, by addressingthe Commissioner of Patents,

Washington, D. G. 

